The present disclosure relates to an optical enhancing device, such as a telescopic observation sighting device or individual shoulder (or hand-fired) firearms sighting device (telescopic sight herein). Embodiments described herein may also be used with any optical enhancing device containing adjusters, such as a microscope, telescope, etc. For purposes of illustration, it will be assumed herein that the optical enhancing device is a telescopic sight.
A telescopic sight, typically used to aim a firearm, is usually mounted on the firearm. An adjustment knob on a telescopic sight is typically used for changing a setting of an adjuster that may change the adjustment of, for example, elevation, crossrange (also “windage” herein), or parallax of the telescopic sight. Parameters such as elevation, crossrange, and parallax may be painstakingly set in order that the firearm hits a specific target. Once set for a particular target, the setting preferably remains unchanged until after a shot is fired.
Existing telescopic sighting systems for civilian, law enforcement, and military firearms typically utilize one or more of three types of adjustment knobs. The first type of adjustment knob, termed a “hunting style” knob, utilizes a cover cap that must be removed prior to adjustment of the sight and replaced after adjustment of the sight to protect the adjustment member of the knob from unintentional adjustment. An advantage of this style of adjustment knob is that it is protected from moisture due to the protection provided by the cover cap. A disadvantage of this type of adjustment knob is that for each adjustment, the cap must be removed and replaced, thereby creating a potential for cap loss.
The second type of adjustment knob is termed a “target style” knob, and is accessible for adjustment at all times. An advantage of this type of adjustment knob is that it is accessible for adjustment at all times without the necessity of removing and replacing a cover cap. A disadvantage is that the adjustment knob can be inadvertently rotated by accidental physical contact.
The third type of adjustment knob is a variation of the “target style” adjustment knob and is a replacement knob used in lieu of the “hunting style” turret knob protective cap. This style of adjustment knob provides a “target style” function, should a marksman choose its use. The advantages and disadvantages of this type of adjustment knob are the same as for the “target style” knob.
What is needed is an adjustment knob that is mechanically lockable, and can be unlocked by an operator when a change in setting is desired.